The present invention is directed to a biological assembly and in particular to a slide and slide cover for use in biological studies.
It is often necessary to examine biological material in order to make quantitative determinations relating thereto. For example, a semen sample may require microscopic study to determine the sperm count in the liquid medium of the sample being observed.
Conventionally, there have been two methods for estimating the number of cells in a suspension. One method uses a hemocytometer wherein the number of cells in a given volume is counted by direct microscopic examination. Another method is the use of an electronic counter wherein the cells of a given volume of a suspension are drawn through an orifice and registered electronically.
The hemocytometer comprises a slide and a precision ground cover slip which covers two ruled areas which are ruled in the form of grids. When the cover slip is pressed down on the slide, a chamber is formed therebetween. A drop of cell suspension is placed at the two edges of the cover slip so that the suspension flows into the chambers by capillary action. Other chambers of this type are known as the Horwell Chamber, the Makler chamber and the Hausser Chamber. These devices must be ground to great precision and thus are expensive to make and are accordingly non-disposable. They are, therefore, cleaned after each use so that they can be reused.
U.S. Pat. No. 4,911,782 discloses a biological slide assembly which enables a fixed volume of sample and liquid medium to be received in a chamber by capillary action in order to be observed under a microscope. The microscope must include a reference grid in the ocular, which is divided into 100 squares, so that the cell count in a representative one of the squares can be obtained by a human observer and used to approximate the total number of cells within the grid. While this device is disposable, it is complex in design and difficult to use in practice.